Push to open drawer slide

ABSTRACT

A push to open drawer slide and drawer having drawer slides thereon can be closed by manually pushing on the drawer slide or the drawer, removing the manual force and subsequently pushing the drawer slide or drawer inward and releasing it, thereby allowing the drawer to be moved to the open position. The drawer slides each have interlocks thereon between an outer channel and an inner channel. The interlocks engage when the drawer slides are closed and disengage when the inner channel is pushed inward and released relative to the outer channel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a push to open drawer slide and to a drawer of a cabinet utilizing push to open drawer slides. More particularly, this invention relates to a drawer slide that has interlocks thereon that engage when said drawer slide is pushed to a closed position and disengage when said drawer slide is pushed inward slightly and released whereupon said drawer slide can be moved to an open position.

2. Description of the Prior Art

Drawer slides of various types and sizes are known. When drawers are located in a cabinet it is known to have one drawer slide on each side of each drawer to enable the drawer to be smoothly opened and closed. The drawer has a handle on a front thereof and the drawer is opened or closed by pushing or pulling on the handle. It is known to have drawer slides with locking mechanisms thereon so that the drawer can be locked or unlocked when it is in a closed position. Push to open latches are known for use on cabinet doors, but they are not used on drawer slides and sometimes fail prematurely when used on doors.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a drawer slide and a drawer utilizing two drawer slides where the drawer slide or drawer can be pushed to a closed position and subsequently pushed inward slightly and then released to open the drawer slide and drawer. It is a flirter object of the present invention to provide a drawer slide having interlocks thereon that engage automatically when said drawer slide is pushed to a closed position and disengage automatically when part of said drawer slide is pushed inward relative to another part, thereby allowing said drawer slide to move to an open position by one or more springs.

The push to open drawer slide comprises at least two channels, being an outer channel and an inner channel that are slidably mounted relative to one another. These two channels each have an interior end and an exterior end, there being a first interlock on the interior end of the outer channel and a second interlock on the interior end of the inner channel. The interlocks correspond to one another and are constructed to engage when the channels are moved to a closed position and to disengage when the inner channel is forced inward from the closed position relative to the outer channel and released, thereby allowing said drawer slide to move to an open position.

A push to open drawer is located in a cabinet, the drawer comprising a front, bottom and two sides. The drawer has a drawer slide along each side, there being two drawer slides. Each drawer slide has at least two channels that are slidably mounted relative to one another. The channels have an interior end and an exterior end. The at least two channels are an outer channel and an inner channel, there being a first interlock on the interior end of the outer channel and a second interlock on the interior end of the inner channel. The interlocks correspond to one another and are constructed to engage when the channels are moved to a closed position and to disengage when the inner channel is forced inward from the closed position relative to the outer channel and released, thereby allowing said slide to move to an open position.

A method of opening and closing a drawer having drawer slides thereon, the method comprising, commencing with the drawer in an open position, manually pushing the drawer to a closed position and removing any manual force from the drawer, thereby locking said drawer, subsequently pushing the drawer inward and releasing the drawer to unlock said drawer, thereby allowing the drawer to be moved to the open position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a drawer slide in a closed position;

FIG. 2 is a side view of the drawer slide in FIG. 1 in a closed position;

FIG. 3 is an end view of the drawer slide in FIG. 1 in a closed position;

FIG. 4 is a top view of the drawer slide of FIG. 1 in an open position;

FIG. 5 is a side view of the drawer slide of FIG. 1 in an open position,

FIG. 6 is a perspective view of a housing having a first interlock thereon;

FIG. 7 is a top view of the housing of FIG. 6;

FIG. 8 is a side view of the housing of FIG. 7;

FIG. 9 is a perspective view of the housing of FIG. 7 when viewed from a bottom;

FIG. 10 is an end view of the housing of FIG. 7;

FIG. 11 is a side view showing detail A from FIG. 8;

FIG. 12 is a top view showing detail B from FIG. 7;

FIG. 13 is a top view of a second interlock;

FIG. 14 is a perspective view of the second interlock;

FIG. 15 is a side view of the interlock of FIG. 13;

FIG. 16 is an end view of the interlock of FIG. 13;

FIG. 17 is an enlarged top view of detail A from FIG. 13;

FIG. 18 is a perspective view of a spring holder;

FIG. 19 is a side view of the spring holder of FIG. 18;

FIG. 20 is a bottom view of the spring holder of FIG. 18;

FIG. 21 is an end view of the spring holder of FIG. 18;

FIG. 22 is a top view of an outer channel;

FIG. 23 is a side view of the outer channel;

FIG. 24 is an end view of the outer channel;

FIG. 25 is a top view of an intermediate channel,

FIG. 26 is a side view of the intermediate channel;

FIG. 27 is an end view of the intermediate channel;

FIG. 28 is a top view of an inner channel;

FIG. 29 is a side view of the inner channel;

FIG. 30 is an end view of the inner channel;

FIG. 31 is a side view of the drawer slide in an open position with the spring holders shown in a depressed position;

FIG. 32 is a schematic top view of a cabinet having a drawer in an open position;

FIG. 33 is a side view of a further embodiment of a push to open drawer slide;

FIG. 34A is a side view of the further embodiment of the drawer slides in a closed position;

FIG. 35 is a perspective view of a further embodiment of a housing have a first interlock therein;

FIG. 36 is a perspective view of an underside of the housing of FIG. 35;

FIG. 37 is a perspective view of a spring casing mounted on the housing of FIG. 35;

FIG. 38 is a side view of the casing;

FIG. 39 is a further embodiment of a second interlock;

FIG. 40 is a side view of the second interlock shown in FIG. 39;

FIG. 41 is an enlarged side view of detail A of FIG. 40;

FIG. 42 is a bottom view of the second interlock shown in FIG. 39;

FIG. 43 is a side view of an inner channel having the second interlock shown in FIG. 39 mounted therein when viewed from a closed side; and

FIG. 44 is a perspective view of an inner channel having a second interlock as shown in FIG. 39 mounted therein when viewed from an open side.

DESCRIPTION OF A PREFERRED EMBODIMENT

In FIGS. 1 to 5, there is shown a drawer slide 2 having an outer channel 4, an inner channel 6 and an intermediate channel 8. The outer channel 4 has an interior end 10 and an exterior end 12. The inner channel 6 has an interior end 14 and an exterior end 16. The intermediate channel 8 has an interior end 18 and an exterior end 20. The drawer slide 2 is shown with three telescoping channels 4, 6, 8, but a drawer slide can have only two channels or more than three channels. The channels are slidably mounted relative to one another and preferably have ball bearing slides 22, 24, between the outer channel 4 and the intermediate channel 8 and between the intermediate 8 and the inner channel 6 respectively. Telescoping drawer slides with two or more channels slidably mounted relative to one another are conventional.

When the drawer slide 2 is in a closed position as shown in FIGS. 1 and 2, the interior ends 10, 14 of the outer channel 4 and inner channel 6 respectively are located nearly directly opposite to one another as shown in FIGS. 1 and 2. When the drawer slide 2 is in an open position as shown in FIGS. 4 and 5, the interior ends 10, 14 of the outer channel 4 and inner channel 6 respectively are located a greater distance apart from one another than the distance shown in FIGS. 1 and 2. The open position shown in FIGS. 4 and 5 is a substantially open position. Any position in which the inner and intermediate channels 6, 8 respectively move outward relative to the outer channel 4 from the position shown in FIGS. 1 and 2 can be considered to be an open position even though the drawer slide 2 might only be slightly open or partially open. There is no drawing showing a drawer slide in a slightly open position.

As best seen from FIG. 5, a housing 26 is affixed to the outer channel 4 at the interior end 10. The housing 26 is shown in much greater detail in FIGS. 6 to 12 and has a base 28 with a central portion 30, interior end 32 and end wall 33 with a vertical opening 34 therein. On either side of the central portion 30, there are grooves 36 containing springs 38 with fittings 40 mounted on an exterior end of the springs 38. On the central portion 30, there is affixed a generally triangular shaped first interlock 42. The first interlock 42 is a catch for a second interlock (not shown in FIGS. 6 to 12). The first interlock 42 has a first surface 44 that crosses an imaginary longitudinal center line of the outer channel 4, a second surface 46 that curves inward and a third surface 48 that is substantially straight. There is a first nodule 50 that is located between the first and third surfaces 44 and 48, and a second nodule 52 located at or near a transition between the second surface 46 and the third surface 48. The nodules 50, 52 are each preferred, but are not essential. Between the second surface 46 and the end wall 33 there is located a guide 54. The guide 54 is preferred, but is not essential. The nodules 50, 52 and the guide 54 improve the performance of the slide 2, but the slide 2 will work without them. The housing 26 has an exterior end 56. In FIGS. 7 to 12, the springs 38 and fittings 40 have been removed from the housing 26. In FIG. 9, an underside 58 of the housing 26 is shown. In FIG. 12, it can be seen that the guide 54 has an angled surface 60 that is located opposite to the curved surface 46 of the first interlock 42. The guide 54 has a triangular shape, but other shapes will also work.

In FIGS. 13 to 17, there is shown a second interlock 64, which is affixed to an underside of the inner channel 6 (not shown in FIGS. 13 to 17) at the interior end 18 thereof (not shown in FIGS. 13 to 17). The second interlock 64 has and exterior end 66 and an interior end 68. The exterior end 66 has a rectangular shaped portion 70 with an opening 72 therein and two ridges 74, there being one ridge along each side of the rectangular portion 70. An elongated member 76 extends from the rectangular portion 70 to the interior end 68 and is angled somewhat to the right when viewed from the rectangular portion 70 in the orientation shown in FIGS. 13 and 14. The interior end 68 of the elongated member 76 has a protrusion 78 extending upward therefrom. As best seen from FIG. 17, the protrusion 78 preferably has a pointed end 80 at the interior end 68 and an angled corner 82 on a left interior corner when viewed from the substantially rectangular portion 70. The second interlock 64 is preferably made from a material that is sufficiently flexible to allow the elongated member 76 to be deflected sideways when the protrusion 78 contacts the first interlock 42 (not shown in FIGS. 13 to 17) and sufficiently resilient or having sufficient memory to return to its original undeflected position as shown in FIGS. 13 to 17 when external forces are removed from the elongated member 76. The second interlock 64 is a latch that interacts with the first interlock 42 to engage and disengage the inner channel 6 and the outer channel 4. Since the second interlock 64 is mounted beneath the inner channel 6, the second interlock 64 is mounted upside down relative to the orientation shown in FIGS. 13 to 17 with the protrusion 78 extending toward the outer channel 4. When viewed from a side of the outer channel 4 shown in FIGS. 2 and 5 (the second interlock 64 not being shown in FIGS. 2 and 5), the elongated member 76 is angled to the left relative to the substantially rectangular portion 70 and relative to the first interlock 42 which is shown in FIG. 5. The ridges 74 are located to abut the fittings 40 (not shown in FIGS. 13 to 17) when the slide 2 is being opened or closed. When the slide 2 is being opened, the springs 38 and fittings 40 push the inner and intermediate channels 6, 8 respectively of the slide 2 outward.

In FIGS. 18 to 21, there are shown various views of one of the fittings 40. The fitting 40 has a cylindrical shaped opening 84 therein for receiving the spring 38 (not shown in FIGS. 18 to 21). From FIGS. 20 and 21, it can be seen that the opening 84 narrows at an exterior end 86 so that the spring 38 will not pass through the exterior end 86. The fitting 40 has an interior end 88 and the spring 38 is inserted into that end. A heel 90 catches on a lip at the exterior end of the groove 36 (not shown) to prevent the fitting 40 from falling out of the groove 36. A ridge 92 along the top maintains an upright orientation as the fitting 40 moves inward within the groove 36 of the housing 26 (not shown in FIGS. 18 to 21, but shown in FIG. 6). An interior end of the ridge 92 has a taper 94 thereon. The taper 94 allows the fittings 40 to travel as close as possible to the interior end 32 of the housing 26 as shown in FIG. 6 and partially under the end wall 33 (but not shown in FIGS. 18 to 21).

FIGS. 22 to 24 are a top view, side view and end view respectively of the outer channel 4. At the interior end 10, there is shown a central tab 96 and two outer tabs 98. The tabs 96, 98 are shown as being straight in FIGS. 22 to 24, but are bent 900 toward the inner channel 6 (not shown in FIGS. 22 to 24) when the channel is in use. In other words, in the top view shown in FIG. 22, the tabs 96, 98 would be bent downward on the page of that drawing in the same direction as the two sides 100 of the channel 4 shown in FIG. 24. The opening 34 in the interior end 32 of the housing 26 (not shown in FIGS. 22 to 24) is sized with the tabs 96, 98 so that the housing 26 can be affixed to the outer channel 4 with the central tab 96 extending into the opening 34 and the interior end 32 fitting between the two outer tabs 98. The housing 26 is not shown in FIGS. 22 to 24.

In FIGS. 25 to 27, there is shown a top, side and end view respectively of the intermediate channel 8. The intermediate channel 8 has a tab 102 that extends into the paper at the interior end 18 and a tab 104 that extends out of the paper at the exterior end 20. The tab 102 is not shown in FIG. 25. The purpose of the tab 102 is to allow a cushion to be mounted on the tab when the interior end 18 of the intermediate channel 8 abuts the housing 26 (not shown in FIGS. 25 to 27) as the drawer slide 2 is moved toward the closed position. The purpose of the tab 104 at the exterior end 20 is to abut the ball bearing slide 24 so that the inner channel 6 will not move outward beyond that Point relative to the intermediate channel 8. The ball bearing slide 24 and the inner channel 6 are not shown in FIGS. 25 to 27.

In FIGS. 28 to 30 there is shown a top, side and end view respectively of the inner channel 6. The inner channel 6 has the interior end 14 and the exterior end 16.

FIG. 31 shows a side view of the drawer slide 2 in the open position and is virtually identical to FIG. 5 except for a position of the springs 38 and fittings 40 of the housing 26. In FIG. 5, the springs 38 and fittings 40 are in the extended position and the fittings 40 extend past the exterior end 56 of the housing 26. In FIG. 31, the springs 38 have been compressed and the fittings 40 have been moved toward the interior end 10 of the outer channel 4, The fittings 40 do not extend beyond the exterior end 56 of the housing 26 even though the slide is in the open position. In FIG. 31, the fittings 40 and springs 38 are in the position they would be in when the drawer slide 2 is in the closed position shown in FIGS. 1 and 2.

in FIG. 32, there is shown a schematic top view of a cabinet 106 having a drawer 108 that is in an open position. The drawer 108 is mounted on the inner channels 6 of two drawer slides 2. There is one drawer slide 2 on each side of the drawer 108. The intermediate channel 8 can also be seen, but the outer channel 4 is not visible as it remains in a fixed position within the cabinet 106 as the drawer 108 slides open and close. The drawer 108 has a front 110, but there is no handle on the outer surface. While a handle could easily be installed and could be used with the drawer slides of the present invention, no handle is required to open and close the drawer.

In operation, as the drawer 108 moves from a fully open position to a closed position, the interior end 18 of the intermediate channel 8 will abut the interior ends 88 of the fittings 40 and the interior end 14 of the inner channel 6 will straddle the fittings 40 and will begin to ride over top of the housing 26. As the drawer 108 continues to be moved toward the closed position, the protrusion 78 on the elongated member 76 will contact the first surface 44 of the first interlock 42. The nodule 50 lengthens the first surface 44 to ensure that the protrusion 78 will travel up the first surface 44. As the drawer 108 continues to move toward the closed position, the protrusion 78 will slide along the first surface 44 until the interior end 14 of the inner channel 6 abuts the end wall 33 of the housing 26. At that point, the closing force on the drawer 108 is removed and the drawer slide 2 moves outward slightly under the force of the compressed springs 38. Simultaneously, the protrusion 78 moves past the first surface 44 and moves left toward the second surface 46 as the elongated member 76 moves partially towards its original position. Depending on how quickly the drawer 108 is closed, the protrusion 78 may be in contact with the right hand surface of the guide 54. In any event, as the drawer slide 2 backs off slightly, the protrusion 78 will move left and contact the second surface 46 of the first interlock 42. The nodule 52 on the left hand side of the second surface 46 prevents the protrusion 78 from moving too far to the left where it would be out of contact with the second surface 46. The elongated member 76 is biased to the left so that when there is no force on the protrusion 78, the protrusion 78 and the elongated member 76 will move toward the left. It is only the angle of the first surface 44 that moves the protrusion 78 and the elongated member 76 to the right as the drawer 108 and the slide 2 are being closed. When the protrusion 78 is in contact with the second surface 46 of the first interlock 42, the drawer slide 2 and the drawer 108 are in the closed position. When it is desired to open the drawer slide 2 or the drawer 108, the drawer 108 is pushed inward which causes the inner channel 6 to move inward back into contact with the end wall 33 of the housing 26. The protrusion 78 is pushed into the angled wall on the left of the guide 54, which causes the protrusion 78 and the elongated member 76 to move left. Even if the guide 54 was not present, the memory or resiliency of the elongated member 76 will cause the elongated member 76 and the protrusion 78 to pivot to the left so that the protrusion 78 will be clear of the second surface 46 and the nodule 52 at the left hand side of the second surface 46. The nodule 52 assists in preventing the protrusion 78 from prematurely moving to the left out of contact with the second surface 46.

When the protrusion 78 has cleared the second surface 46 including the nodule 52 at the left hand side of the second surface 46, the springs 38, which are compressed when the drawer 108 is closed, force the inner channel 6 and the intermediate channel 8 outward by approximately the length of the housing 26. This allows the drawer 108 to be easily opened manually the rest of the way.

For drawer slides which have more or fewer than three channels, variations may have to be made in the manner that the slides interact with the housing. Numerous variations can be made to the drawer slide of the present invention and will be readily apparent to those skilled in the art. For example, while specific interlocks have been described in detail with the present invention, other types of interlocks will work as well. In addition, the design can be changed so that the first interlock, which is the catch, and the second interlock, which is the latch, are interchanged so that the latch is on the housing and the catch is on the inner channel. Preferably, the second interlock is made of a plastic material which has sufficient flexibility to be deflected sideways by the first interlock and sufficient memory to return to its original position when the forces from the first interlock have been removed. The interlocks of the present invention have been designed so that the drawer slide will still operate properly even if the second interlock loses all or some of its memory.

FIGS. 33 to 44, inclusive, describe a further embodiment of the invention in which interlocks on the inner channel and outer channel respectively have a different design from the interlocks described in FIGS. 1 to 32. The channels are conventional and are the same for all of the drawings except for small differences that may be necessary in order to fix the interlocks to the channels. The interlock design shown in FIGS. 33 to 44 is the preferred embodiment.

The same reference numerals are used in FIGS. 33 and 34 as those used in FIGS. 1 to 5 for those components that are identical. The channels 4, 6, 8 are telescoping channels that are often described as C-shaped channels that are mounted within a cabinet (not shown) on either side of each drawer (not shown). In FIG. 33, a drawer slide 112 is shown in an open position with a first interlock 114 located in a housing 116 mounted at die interior end 110 of the outer channel 4. A second interlock 118 is partially shown and is mounted at the interior end 14 of the inner channel 6. The push to open slide 112 operates in an identical manner as the push to open slide 2 from the point of view of a user in that the interlocks engage one another when the inner channel 6 is moved to a closed position as shown in FIG. 34A relative to the outer channel 4.

The housing 116 is best shown in FIGS. 35 and 36 in which FIG. 35 is a perspective view of the housing 116 with a view from above and FIG. 36 is a perspective view of the housing 116 with a view from below. The housing 116 is sized and shaped to be mounted in a fixed position within the outer channel 4 (not shown in FIGS. 35 and 36) in which a tab (not shown) of the outer channel 4 extends through the opening 34 at an inner end 120 of the housing 116. An outer end 122 of the housing 116 is preferably held in place with tabs (not shown) in the drawings of the outer channel 4 that fit over the outer corners 124 at the outer end 122 of the housing 118. The housing 116 supports the first interlock 114.

A casing 126 contains two springs 128 and is slidable within an appropriately shaped groove 130 located in the bottom of the housing 1116. The springs 128 can be designed and located in a manner similar to the springs 38 shown in FIG. 6 for the housing 26, but the arrangement of the springs and casings shown in FIGS. 35 and 36 is preferred. The casing 126 and springs 128 of FIGS. 35 and 36 can easily be incorporated into the housing 26 if desired in place of the spring arrangement shown in FIG. 6. The first interlock 114 has an element 132 located adjacent to the first interlock 114 toward the outer end 122 of the housing 16. The element 132 is shaped and located to guide the second interlock 118 (not shown in FIGS. 35 and 36) into the first interlock 114 when the inner channel 6 moves to the closed position relative to the outer channel 4. The element 132 is pivotally mounted about a pivot axis 134 and has a rounded inner end which tapers to a point at an outer end 136, The outer end 136 of the element 132 preferably extends downward therefrom into an arc shaped opening 138. The arc shaped opening 138 limits the pivotal movement of the element 132 about the pivot axis 134. In the position shown in FIG. 35, the element 132 is shown at a lower limit of the channel 138 in that the outer end 136 of the element 132 has moved into contact with a lower end of the channel 138 when the housing 116 is orientated in a vertical plane with a right hand side down when viewed from the inner end 120 to the outer end 122. The inner end 120 has a wall 140 that provides a stop for the interior end 14 of the inner channel 6 (not shown in FIGS. 35 and 36) when the inner channel 6 is in a closed position relative to the outer channel 4.

A guide 142 is triangularly shaped and extends towards the outer end 122 from the wall 140 to guide the second interlock 118 (not shown in FIGS. 35 and 36) into the first interlock 114 at an inner end thereof. The first interlock 114 has a U-shaped cradle 144. The U-shaped cradle 144 and the guide 142 are symmetrical about an imaginary longitudinal center line through the housing 116. The casing 126 has a flange 146 at an inner end thereof so that the casing 126 cannot slide out of the groove 130. The flange 146 has a cross-sectional shape corresponding to the cross-sectional shape of the groove 130 so that the casing 126 will slide smoothly along the groove 130 as the springs 128 expand or contract in response to the movement of the channels 4, 6, and 8 (not shown in FIGS. 35 and 36) relative to one another. There are two posts 148 located within the groove 130 upon which the springs 128 are mounted. The posts 148 maintain the springs 128 in longitudinal alignment with one another as the springs 128 contract and prevent the springs 128 from buckling.

W Returning to FIG. 33, the intermediate slide 8 has a bumper 129 at the inner end 18 to abut the casing 126 and push the casing inward against the force of the springs 128 (not shown in FIG. 33) when the slide is closed.

The casing 126 is shown in FIGS. 37 and 38, the casing 126 has hollowed out portions 150 to receive the springs 128 (not shown in FIG. 37). The hollowed out portions 150 each have narrow sections 152 to hold the springs 128 within the casing 126. An extension 154 is located at an end opposite to the flange 146 to provide a contact for the interior end 18 of the intermediate channel 8 (not shown in FIGS. 37 and 38) when the inner channel 6 moves to a closed position relative to the outer channel 4.

In FIGS. 39 to 41, there is shown the second interlock 118, which has an outer end 156 and an inner end 158. The inner end 158 has a protrusion 160 extending downward therefrom in the orientation shown in FIG. 39. An opening 162 is located near the outer end 156 to enable the second interlock 118 to be pivotally mounted within the inner channel 6 (not shown in FIGS. 39 to 42). From detail A on FIG. 40, which is enlarged in FIG. 41, and from FIG. 42, it can be seen that the second interlock 118 has two legs 164 mounted on an upper surface thereof. The two legs 164 contact an inner surface of the inner channel 6 when the second interlock 118 is pivotally mounted therein and reduce the friction between the second interlock 118 and the surface of the inner channel 6 which makes it easier for the second interlock 118 to pivot relative to the inner channel 6.

In FIGS. 43 and 44, there is shown a side view of the inner channel 6 when viewed from a closed side and a perspective view of the inner channel 6 when viewed from an open side respectively. In FIG. 43, the second interlock 118 is shown by way of dotted lines to be pivotally mounted about a pivot axis 166 near the interior end 14 of the inner channel 6. By gravity, the second interlock 118 has pivoted downward in FIG. 43 to contact an inner surface 168 of the inner channel 6 that is the lower inner surface. In FIG. 44, the same reference numerals are used as those used in FIG. 43 for those components that are the same, and the second interlock 118 is shown to be in the same position as that shown in FIG. 43. The lower inner surface 168 in FIG. 44 is actually the upper inner surface since the inner channel 6 has been flipped over relative to the position shown in FIG. 43. By gravity, in operation, the second interlock 96 will pivot downward so that the protrusion 160 is adjacent to either the inner surface 168 or an inner surface 170, which is lower.

In operation of the embodiment shown in FIGS. 33 to 44, the first interlock 114 can be referred to as a catch and the second interlock 118 can be referred to as a latch. While the drawer slide 112 is described as having three channels, it can be designed to have only two channels or more than three channels. Commencing with the drawer slide in an open position as shown in FIG. 33, as the inner channel 6 is pushed inward, the intermediate channel 8 will also move inward relative to the outer channel 4 until ultimately, the three channels 4, 6, 8 will be in a closed position as shown in FIG. 34 and the casing 126 will have been pushed into the housing 1116 by the interior end 18 of the intermediate channel 8. In other words, the springs 128 will be contracted. As the inner channel 6 slides toward the interior end 10 of the outer channel 4, the protrusion 160 will contact an upper tapered surface of the element 132 and will slide along that surface past the pivot axis 134 and past the rounded end of the element 132 and along a top of the first interlock 114. When the protrusion 160 is beyond an inner upper corner of the top surface of the first interlock 92, the inner end 158 of the latch will pivot downward and the protrusion 160 will contact the upper angled surface of the guide 142. Simultaneously, the interior end 14 of the inner channel 6 will abut against the end wall 140. The inward force against the inner channel 6 will then be released and the springs 128 will cause the inner channel 6 to move slightly outward with the protrusion 160 nested in the U-shaped cradle 144 of the catch. In this position, the slide 112 is in the closed position and the two interlocks 114, 118 are lockingly engaged with one another.

When it is desired to open the slide 112, the inner channel 6 is forced inward slightly and the inward force is immediately released. When the inner channel 6 is forced inward, the protrusion 160 falls downward out of the U-shaped cradle 144 and may contact the lower angled surface of the guide 142 where it is forced downward and by gravity falls below the lower surface of the first interlock 114. In this position, the interlocks 114, 118 are disengaged from one another and the force of the springs 128 will move the channels 4, 6, 8 outward relative to one another to an open position as the springs 128 expand and there is no inward force being applied to the inner channel 6. The distance that the inner channel 6 will spring outward depends on the length and force exerted by the springs 128, but it can easily be two inches or more. The inner channel 6 can then manually be pulled outward to further open the slide 112 and ultimately, if desired, to move the slide 112 to the fully open position shown in FIG. 33.

The embodiment shown in FIGS. 33 to 44, can be redesigned so that the first interlock 114 which is the catch, and the second interlock 118 which is the latch, are interchanged so that the latch is on the housing 116 and the catch is on the inner channel 6. The preferred embodiment is that the catch will be on the housing 116 and the latch will be on the inner channel 6. The free end of the element 132 is asymmetrical about a longitudinal center line through the drawer slide as a element 132 will always pivot by gravity toward the lower edge of the slide 112. When drawer slides are mounted on either side of a drawer or drawers within a cabinet, the drawer slides are side mounted and there is one slide on each side of each drawer. Two or more drawer slides 112 can be substituted for the drawer slides 2 in FIG. 32. The drawer slides on the right hand side of a cabinet are oriented as mirror images of the drawer slides on the left hand side of the cabinet. The element 132 extends across the longitudinal center line by a sufficient distance so that it will contact the protrusion on the second interlock which will always fall by gravity to the lower edge of the inner channel depending on whether the drawer slide is mounted on the left hand side of the drawer or the right hand side of the drawer. The element 132 will always pivot downward by gravity depending on which side of the drawer the drawer slide is mounted.

When the drawer, on which the drawer slides are mounted, moves from an open position to a closed position, the protrusion of the second interlock on each of the drawer slides will move across the longitudinal center line above the second interlock until the drawer is in a closed position and the interlocks have lockingly engaged with one another. In the closed position, the protrusions of both drawer slides will be substantially symmetrical with the longitudinal center line of the slides, but the element will still be pivoted to the downward position. A face of the drawer does not require a handle as the drawer can be opened by manually pushing on the face of the drawer and then removing the inward force. The drawer will spring open a few inches and a user can then manually pull the drawer her open.

An advantage of having the element pivot is that the drawer slides 112 can all be manufactured to be identical to one another and each drawer slide manufactured can be used on either the left hand side or the right hand side of a drawer. It is therefore not necessary to manufacture half the drawer slides 112 as left hand drawer slides and half the drawer slides 112 as right hand drawer slides. The drawer slides 112 can all be identical to one another and can be used as left hand or right hand drawer slides. Another advantage of having the element 132 pivot is that, when the protrusion of the latch has been released from the catch and the inner channel moves outward relative to the outer channel, the protrusion can easily slide past the lower edge of the element 132 and, if necessary, the element 132 will pivot upward slightly under the force of the protrusion passing beneath it. The interlocks of the present invention can be designed so that the element 132 is in a fixed position (and does not pivot about an inner end) at an angle to the longitudinal center line of the slide to guide the protrusion into locking engagement with the catch when the slide is closed However, if element 110 does not pivot then a first fixed design will have to be constructed for left hand slides and a second fixed design, which would be a mirror image of the first fixed design, will be used for right hand slides. The lower portion of the element can be made to flex slightly (in the design that does not pivot about the inner end) if necessary, to allow the protrusion of the second interlock to pass by the element when the slides are being opened.

Preferably, the drawer slides, the element 110, and the second interlock 118 are made from metal and the housing and casing are made from plastic. The springs are preferably made from metal. Both fixed designs as well as other variations will be within the scope of the claims. 

I claim:
 1. A push to open drawer slide comprising at least two channels, being an outer channel and an inner channel slidably mounted relative to one another, said at least two channels each having an interior end and an exterior end, there being a first interlock on said interior end of said outer channel and a second interlock on said interior end of the said inner channel, said interlocks corresponding to one another and being constructed to engage when said channels are moved to a closed position and to disengage when said inner channel is forced inward from said closed position relative to said outer channel and released, thereby allowing said drawer slide to move to an open position.
 2. A drawer slide as claimed in claim 1 wherein one of said interlocks has an element to guide another of said interlocks into engagement with said one interlock.
 3. A drawer slide as claimed in claim 2 wherein one of said interlocks is a catch and another of said interlocks is a latch, said element being located with said interlock that is a catch.
 4. A drawer slide as claimed in claim 3 wherein said first interlock is a catch and said second interlock is a latch.
 5. A drawer slide as claimed in claim 3 wherein said latch is movable relative to said channel in which said interlock is located.
 6. A drawer slide as claimed in claim 5 wherein said element is movable relative to said channel in which said element is located.
 7. A drawer slide as claimed in claim 1 wherein said inner channel is forced inward only slightly from said closed position relative to said outer channel and released to allow said drawer slide to move to an open position.
 8. A drawer slide as claimed in claim 4 wherein said first interlock is contained in a housing affixed to said interior end of said outer channel.
 9. A drawer slide as claimed in claim 5 wherein said catch has a generally triangular shape with an inwardly curved surface facing an interior end of said outer channel.
 10. A drawer slide as claimed in claim 5 wherein said latch has an elongated member extending toward said inner end of said inner channel with a protrusion at a free end of said elongated member to engage said catch.
 11. A drawer slide as claimed in claim 3 wherein said first interlock is contained on a housing affixed to said inner channel near said interior end of said inner channel.
 12. A drawer slide as claimed in claim 3 wherein said catch has a U-shaped cradle facing said interior end.
 13. A drawer slide as claimed in claim 12 wherein said slide is a side-mounted slide and said element is pivotally mounted to provide a guiding surface that extends across a longitudinal center line of said outer channel whether said slide is mounted on a left hand side or a right hand side.
 14. A drawer slide as claimed in claim 12 wherein said element is pivotally mounted at an interior end of said channel, said element being located immediately adjacent to said first interlock toward an exterior end of said channel.
 15. A drawer slide as claimed in claim 13 wherein said element tapers toward an exterior end of said element.
 16. A drawer slide as claimed in claim 1 wherein said inner channel backs off slightly when engaged, from a position of said inner channel immediately prior to engagement.
 17. A drawer slide as claimed in claim 1 wherein said first interlock is mounted on a housing located at an interior end of said outer channel and there is at least one spring located in said housing, said spring being biased to move said drawer slide to said open position when said interlocks are disengaged after being engaged.
 18. A drawer slide as claimed in claim 10 wherein said catch has a nodule at an apex of said generally triangular shape opposite to said interior end, said nodule lengthening a first surface of said generally triangular shape, said first surface being located to be contacted by said longitudinal member of said latch when said drawer slide moves toward said closed position.
 19. A drawer slide as claimed in claim 17 wherein said generally triangular shape has a first surface, a second surface that is said concave surface and a third surface, said protrusion of said elongated member contacting said first, second and third surfaces chronologically when moving toward said closed position and from said closed position to said open position, said drawer slide being in said closed position with said latch being engaged with said catch when said protrusion is in contact with said second surface.
 20. A drawer slide as claimed in claim 18 wherein there is a second nodule at or near an end of said concave surface where said concave surface meets the third surface.
 21. A drawer slide as claimed in claim 10 wherein said elongated member is biased to disengage said interlocks when said elongated member is not subject to any external force.
 22. A drawer slide as claimed in claim 18 wherein there is a guide located opposite said inwardly curved surface, said guide being shaped to move said elongated member to an open position.
 23. A drawer slide as claimed in claim 2 wherein said second interlock has an inner end and an outer end, said second interlock being pivotally mounted in said inner channel at said inner end, said inner channel being side-mounted and said second interlock having a protrusion at said inner end extending toward said first interlock, said protrusion engaging said first interlock when said interlocks are engaged and disengaging from said first interlock when said interlocks are disengaged.
 24. A drawer slide as claimed in claim 23 wherein said protrusion is located to contact said element as said inner channel approaches said outer channel, said protrusion being guided into engagement with said first interlock.
 25. A drawer slide as claimed in claim 24 wherein said second interlock is pivotally mounted to allow said slide to be mounted on a left hand side or a right hand side of a drawer.
 26. A drawer slide as claimed in claim 10 wherein said elongated member is made from a flexible and resilient material, said elongated member being flexible enough to swing sideways when subjected an external force and sufficiently resilient to return to an initial position when said external force is removed.
 27. A drawer slide as claimed in claim 10 wherein said elongated member is flexible enough to move sideways and is made from a material that has a memory so that said elongated member will return to its initial position when external forces are removed.
 28. A drawer slide as claimed in claim 3 wherein said catch has an element located to guide said latch into said catch as said inner channel moves to a closed position relative to said outer channel.
 29. A drawer slide as claimed in claim 1 wherein said interlock on said outer channel has an element located on an outer end of said interlock, said element being shaped to guide said interlock on said inner channel into a releasable locking engagement with said interlock on said outer channel when said inner channel is moved from said open position into said closed position relative to said outer channel.
 30. A drawer slide as claimed in claim 8 wherein there is an element shaped and located to guide said latch into said catch from a top of said catch when said inner channel is moving to said closed position, said latch being released from a bottom of said catch when said inner channel is forced inward from said closed position.
 31. A drawer slide as claimed in claim 8 wherein said channels are telescopingly mounted within one another, said first interlock having an element that is asymmetrical about a longitudinal center line of said first interlock in said outer channel.
 32. A drawer slide as claimed in claim 31 wherein said there are two drawer slides, each drawer slide being mounted along a side of a drawer, said drawer slides being identical to one another, said element being pivotally mounted so that an inner end of said element can pivot downward to guide said second interlock into said first interlock when said slides are moved from an open position to a closed position.
 33. A drawer slide as claimed in claim 8 wherein said channels are telescopingly mounted within one another, said first interlock having a element that extends at an angle across a longitudinal center line of said first interlock in said outer channel to guide said latch into said catch when said inner channel moves to a closed position relative to said outer channel.
 34. A drawer slide as claimed in claim 1 wherein said slide is oriented in a vertical plane and said first interlock and second interlock are constructed to cause said second interlock to enter said first interlock from a top thereof when said slide is being closed and to exit through a bottom of said first interlock when said slide is being opened.
 35. A push to open drawer slide comprising at least two channels, being an outer channel and an inner channel slidably mounted relative to one another, said at least two channels each having an interior and an exterior end, there being a first interlock on said interior end of said outer channel and a second interlock on said interior end of said inner channel, said interlocks corresponding to one another and being shaped and constructed to releasably interlock with one another in an engaged position when said inner channel is moved to a closed position from an open position relative to said outer channel, said interlocks being shaped and constructed to disengage from one another when said inner channel is pushed inward from said interlocked position and released, thereby allowing said drawer slide to move to an open position.
 36. A drawer slide as claimed in claim 35 wherein one of said interlocks has a latch that is movable relative to the channel on which said latch is mounted and another of said interlocks has an element to guide said latch into said engaged position with the other interlock, said element being movable relative to said channel in which said element is mounted.
 37. A drawer slide as claimed in claim 36 wherein said latch has an outer end that is pivotally mounted in said inner channel and said element has a inner end that is pivotally mounted in said outer channel.
 38. A drawer slide as claimed in claim 37 wherein said drawer slide can be mounted on a left hand side or a right hand side of a drawer without making any changes in structure to said slide.
 39. A drawer slide as claimed in claim 35 wherein there is at least one spring to move said channels to said open position when said interlocks initially become disengaged.
 40. A push to open drawer located in a cabinet, said drawer comprising a front, bottom and two sides, said drawer having a drawer slide along each side, there being two drawer slides, each drawer slide having at least two channels that are slidably mounted relative to one another, said channels having an interior end and an exterior end, said at least two channels being an outer channel and an inner channel, there being a first interlock on said interior end of said outer channel and a second interlock on said interior end of said inner channel, said interlocks corresponding to one another and being constructed to engage when said channels are moved to a closed position and to disengage when said inner channel is forced inward from said closed position relative to said outer channel and released, thereby allowing said drawer slide to move to an open position.
 41. A method of closing and opening a drawer having drawer slides thereon, said method comprising, commencing with the drawer in an open position, manually pushing the drawer to a closed position and removing all manual force from said drawer, thereby locking said drawer, subsequently pushing said drawer inward and releasing said drawer to unlock said drawer, thereby allowing said drawer to be moved to the open position.
 42. A method of closing and opening a drawer having drawer slides thereon, said drawer slides being mounted on each side of said drawer, said slides each having at least two channels that are telescopingly mounted relative to one another, there being one inner channel and one outer channel, each channel having an inner end and an outer end with a first interlock being mounted at said inner end of said outer channel and a second interlock being mounted at an inner end of said inner channel, an element being constructed and located on one of said channels to guide said interlocks into an interlocked position when said inner channel moves to a closed position relative to said outer channel, said interlocks moving out of said interlock position to a released position when said drawer is forced inward from said interlocked position and released, said method comprising commencing with the drawer in an open position, pushing the drawer inward to a closed position and removing all manual force from said drawer to lock said drawer in said interlocked position, subsequently pushing said drawer inward to release said drawer from said interlocked position, thereby allowing said drawer to be moved to said open position. 